This invention relates to cooling water systems and, more particularly, to a method for protecting cooling water systems from contamination by monitoring hydrocarbon concentrations within a flowing aqueous solution and activating alarms or shutdown procedures accordingly.
Cooling towers are devices frequently used in chemical, refining, and power production industries for cooling a liquid, typically water, which has become heated as a result of being circulated about a hot fluid stream such as petroleum products. Following this heat exchange, the heated water is returned to the cooling tower where it is exposed to an upward air stream to facilitate cooling prior to recirculation. Impurities in industrial cooling waters is a significant problem which may lead to scaling, fouling, and corrosion of heat exchange equipment, pipelines, or the cooling tower itself. Consequently, these problems result in economic disadvantages such as early replacement of equipment, energy waste due to decreased heat transfer efficiency, extended or unscheduled downtime, and environmental pollution through evaporation of impure cooling water. Impurities such as hydrocarbons often enter the cooling water system through leakage of process fluids such as petroleum products during the heat exchange process.
Various methods and devices have been proposed in the prior art for detecting the presence of hydrocarbons in a reservoir of water such as a cooling tower or testing vessel. Although assumably effective in operation, such known methods and devices require periodic human assessments of water purity before the industrial process may be halted to prevent damage to equipment or the environment. Further, other known methods merely add corrosion inhibiting chemicals to the cooling waters for protecting equipment without identifying the source of the impurity for corrective purposes.
Thus, it is desirable to have a method for continuously monitoring circulating cooling waters for the presence of impurities within a cooling water system. It is also desirable to have a method for monitoring cooling waters which automatically halts circulation of both the process and cooling streams within the polluted segment of the system upon sensing a predetermined impurity level.